An abdominal aortic aneurysm (AAA) is a swelling in the abdominal aorta, which is the main artery that supplies blood to your body. As the AAA grows, the wall of the aorta stretches and becomes weaker, which can eventually lead to a significant risk of a ruptured AAA. This is often fatal. The aim of the AAA screening programme is to reduce AAA-related mortality by providing a systematic, population-based screening programme.